1. Field of the Invention
The present invention relates to an ink jet printer that ejects ink to form images on a recording medium and more particularly to an ink jet printer including an ink cartridge for holding ink supplied to the print head, the ink cartridge being formed with an atmosphere communication hole for easing supply of ink to the print head.
2. Description of the Related Art
One conventional ink jet printer has a cap unit with a sealing cap and an ink absorption member. The cap is for providing an intimate sealed condition around the ink ejection surface of the print head. A negative pressure can be applied in the space surrounded by the cap and the ink ejection surface while the cap sealingly covers the ink ejection surface. The negative pressure sucks ink from nozzles in the ink ejection surface of the print head. The cap can prevent ink from splattering around during flushing operations, wherein ink is forcibly ejected from the print head. The ink absorption member absorbs ink sucked out from or ejected from the print head so that ink can be prevented from overflowing out of the cap.
One type of known ink jet printer uses an ink cartridge that holds ink for supply to the print head. The print head ejects ink held in the ink cartridge in order to form images on a recording medium, such as a paper sheet. When ink in one ink cartridge is all used up, that ink cartridge is replaced with a new one so that image forming operations can be continued. Further, the ink cartridge can be provided with an atmosphere communication hole for easing supply of ink from the ink cartridge to the print head. By bringing the inside of the ink cartridge into fluid communication with atmosphere through the atmosphere communication hole, ink can be smoothly supplied from the ink cartridge to the print head so that blurry images and other problems related to unsmooth supply of ink can be prevented.
However, the above-described conventional configurations have problems. For example, ink can overflow from the cap even if an ink absorbing member is provided in the cap. That is, ink that was once absorbed by the ink absorbing member can overflow out of the cap. To overcome this problem it is conceivable that the ink in the ink absorption member be sucked out and collected using a pump, for example. However, even with this conceivable configuration, ink can still overflow from the cap if the ink absorption member absorbs an excessive amount of ink. Another potential remedy to the problem of ink overflow is to dispose the print head with its ink ejection surface facing directly downward and to dispose the cap with its open portion facing directly upward. However, this remedy only works if the ink jet printer itself is perfectly level on a flat surface. If the ink jet printer itself is oriented with a tilt, then both the ink ejection surface and the cap will tilt also. Also, this remedy limits freedom of design because in some situations it is desirable to design the ink jet printer so that the ink ejection surface is vertically oriented.
Providing an atmosphere communication hole to ink cartridges eases supply of ink, but also increases the risk of ink leaking from the print head. For example, ink can leak out of the print head when the ink jet printer is vibrated or shocked, for example by being carried around or otherwise transported. One potential remedy for this problem is to cover the print head with the above-described cap while the ink jet printer is transported. However, if the cap becomes separated from the print head because the ink jet printer is tilted at an angle, subjected to shock or vibration, or for some other reason, then ink will leak out from the print head. Therefore, merely covering the print head with the cap while transporting the ink jet printer is not a sufficient prevention for such ink leaks.
It is an objective of the present invention to provide a cap device capable of properly preventing ink from overflowing out from the cap of the cap device after the ink was sucked out or ejected from a print head of an ink jet printer into the cap. It is another objective of the present invention to provide an ink jet printer that uses ink cartridges formed with an atmosphere communication hole, but that does not leak ink when the ink jet printer is transported.
In order to achieve the above-described objectives, a cap device according to the present invention includes a cap, an ink absorption member, and a lid. The cap is for developing a seal around an ink ejection surface of a print head. The ink absorption member is disposed in the cap to absorb ink that was ejected or sucked from the print head into the cap. The lid covers an ink-ejection-surface-confronting portion of the ink absorption member except at least a nozzle-confronting portion of the ink absorption member. The lid is connected to an inner peripheral surface of the cap with a fluidly tight connection.
With this configuration, the lid, which is connected to the inner peripheral surface of the cap with a fluidly tight connection, covers the upper surface of the ink absorption member except at least the nozzle-confronting portion of the upper surface. For this reason, if the ink jet printer is used while the portion of the ink absorption member that is covered by the lid is disposed lower than the other portions, even if only because the cap and the ink absorption member are tilted slightly, the lid will dam up any potential flow of ink that is once absorbed the ink absorption member.
Accordingly, the cap device according to the present invention can properly prevent ink that was ejected from or sucked from the print head into the cap, from overflowing from the cap. It should be noted that the lid covers the ink absorption member except at the nozzle-confronting portion of the ink absorption member, nozzle flushing and suction operations can be performed properly in the conventional manner.
It is desirable that the lid covers the entire ink-ejection-surface-confronting portion of the absorption member except the nozzle-confronting portion of the ink absorption member. When the lid covers all of the upper surface of the ink absorption member except the nozzle-confronting portion, the lid properly dams up ink in the ink absorption member and can properly prevent ink from overflowing from the cap regardless of what direction the cap is tilted.
A cap device according to another aspect of the present invention also includes a cap, an ink absorption member, and a lid. In this case, the cap has a base and an inner peripheral surface. The base and the inner peripheral surface define an inner space and an open side of the cap. The open side is in confrontation with the base. The cap develops a seal around the ink ejection surface of the head when the cap is in intimate contact with the head while the head is located at the open side. The ink absorption member is disposed at the base of the cap to absorb ink that was ejected or sucked from the head into the cap from the open side of the cap. The ink absorption member has an upper surface facing the open side of the cap from inside the cap. The upper surface has an nozzle-confronting portion at a position that confronts the nozzles of the head when the cap is in an intimate seal with the ink ejection surface of the head. The lid covers the upper surface of the ink absorption member except at least the nozzle-confronting portion of the upper surface. The lid is connected to the inner peripheral surface of the cap with a fluidly tight connection.
An ink jet printer according to the present invention includes a head, a cap, an ink absorption member, and a lid. The head has an ink ejection surface formed with nozzles. The cap is for developing a seal around the ink ejection surface of the print head. The ink absorption member is disposed in the cap to absorb ink that was ejected or sucked from the print head into the cap. The lid covers an ink-ejection-surface-confronting portion of the ink absorption member except at least a nozzle-confronting portion of the ink absorption member. The lid is connected to an inner peripheral surface of the cap with a fluidly tight connection.